三角函数

来源:互联网 发布:俄克拉何马爆炸案 知乎 编辑:程序博客网 时间:2024/03/29 15:14
#include <iostream>#include<cmath>using namespace std;const double pai=3.1415926;double mysin(double);double mycos(double);double myjds(double);int main(){cout<<"sin(π/2)的值为:"<<mysin(pai/2);cout<<",利用库函数求的sin(π/2)的值为:"<<sin(pai/2)<<endl<<endl;cout<<"sin(56°)的值为"<<sin((56.0/180)*pai);cout<<",利用库函数求的sin(56°)的值为:"<<endl<<endl;cout<<"cos(87°)的值为:"<<mycos((87.0/180)*pai);cout<<",利用库函数求的cos(87°)的值为:"<<endl<<endl;cout<<"cos(π/3)的值为:"<<mycos(pai/3);cout<<",利用用库函数求的cos(π/3)的值为:"<<cos(pai/3)<<endl;return 0;}double mysin(double x){double sum=1,x_pow=1,t;int n=1,g=1,r=1;do{g=g*(n+1)*(n+2);x_pow=x*x;r=-r;t=x_pow/g*r;sum+=t;n+=2;}while(myjds(t)>0.00001);return sum;}double mycos(double x){double sum=1,x_pow=1,t;int n=0,g=1,r=1;do{g=g*(n+1)*(n+2);x_pow=x*x;r=-r;t=x_pow/g*r;sum+=t;n+=2;}while(myjds( t)>0.00001);return sum;}